FTFY
> Kick out poll watchers
Were any poll watchers kicked out? Trump's claim that there weren't poll watchers in Pennsylvania all turned out to be false; their lawyer admitted in court that they actually had 19 observers in the room [1].
EDIT Meanwhile, the graphs in TFA shows that there are "bumps" in the curve, showing that Democratic-leaning counties had lower turnout in the 2016 election. This is consistent with the widespread reports of Republicans trying to suppress the vote in Democratic-leaning areas, of which [2] and [3] are more recent examples.
[1] https://news.bloomberglaw.com/us-law-week/trump-sues-to-halt...
[2] https://www.theguardian.com/us-news/2020/jan/01/north-caroli...
[3] https://www.texastribune.org/2020/11/01/texas-drive-thru-vot...
2. Kick out poll watchers
3. Figure out how many votes your preferred candidate needs.
4. Examine the voter rolls and see who never turned in a ballot.
5. Fill in ballots for those people (and if you're in a rush, don't even bother to vote in any down-ballot races) and mix them in with the legitimate ballots.
If you control a few key urban centers in a few key states - you can definitely pull this off. Given the behavior of the left over the last 4 years, I absolutely believe they did something like the above.